A packaging apparatus for forming sealed packages

ABSTRACT

A packaging apparatus for forming sealed packages filled with a pourable product comprises a delimiting element movably arranged, in use, within a tube and designed to divide the tube in a first space and a second space. The delimiting element is movable along first and second directions opposite one another and substantially parallel to the tube, and between at least a first position and a second position. The delimiting element comprises a main engagement portion configured to abut against a main abutment portion of a gas supply pipe or a filling pipe with the delimiting element being in the first position. The main abutment portion and/or the main engagement portion are designed such that at least one opening and/or at least one channel is present between the main abutment portion and the main engagement portion with the delimiting element being in the first position.

TECHNICAL FIELD

The present invention relates to a packaging apparatus for forming sealed packages, in particular for forming sealed packages filled with a pourable product.

BACKGROUND ART

As is known, many liquid or pourable food products, such as fruit juice, UHT (ultra-high-temperature treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by sealing and folding a laminated strip packaging material. The packaging material has a multilayer structure comprising a base layer, e.g. of paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material, e.g. an aluminum foil, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

Packages of this sort are normally produced on a fully automatic packaging apparatus, which advances a web of packaging material by means of a conveying device through a sterilization unit for sterilizing the web of packaging material, e.g. by means of chemical sterilization (e.g. by applying a chemical sterilizing agent, such as a hydrogen peroxide solution) or physical sterilization (e.g. by means of an electron beam). Then, the sterilized web of packaging material is maintained and advanced within an isolation chamber delimiting an inner environment, and is folded and sealed longitudinally within the inner environment to form a tube, which is further fed along a vertical advancing direction.

In order to complete the forming operations, the tube is filled through a filling pipe with a pourable food product, and is transversally sealed and subsequently cut along equally spaced transversal cross sections within a package forming unit of the packaging apparatus during advancement along the vertical advancing direction.

Pillow packages are so obtained within the packaging apparatus, each pillow package having a longitudinal sealing band and a top transversal sealing band and a bottom transversal sealing band.

A type of packaging apparatus comprises:

-   -   a delimiting element being, in use, arranged within the tube and         dividing the tube in a first space being in fluidic connection         with the inner environment and a second space being arranged         downstream of the first space; and     -   a sterile gas supply device configured to direct a sterile gas         into the second space and to control a pressure of the sterile         gas being greater than the pressure within the isolation         chamber.

The delimiting element comprises a passage through which the filling tube extends keeping an annular space between the filling tube and a rim delimiting the passage.

Furthermore, the sterile gas supply device comprises a gas supply pipe coaxial to the filling pipe. In particular, the filling pipe extends partially within the gas supply pipe and out of the gas supply pipe and through the passage so that, in use, the sterile gas to be fed into the second space flows through a ring-shaped channel as delimited by the filling pipe and the gas supply pipe.

In order to accommodate for the inherent fluctuations occurring during the packaging process, the delimiting element is moveable along a first direction and a second direction opposite to the first direction. Both the first direction and the second direction being parallel to the vertical advancement direction.

In use, the delimiting element is lifted by means of the sterile gas being present within the second space and the delimiting element is movable along the first direction until a first engagement portion of the delimiting element abuts against a first abutment portion of the gas supply pipe and is movable along the second direction until a second engagement portion of the delimiting element abuts against a second abutment portion of a support element being arranged below the delimiting element.

It has been observed that when the first engagement portion is detached from the first abutment portion a leakage flow of gas from the second space into the inner environment occurs through the ring-shaped channel and a space being present between the delimiting element and the gas supply pipe, while there is no leakage flow when the first engagement portion abuts against the first abutment portion.

It has been further observed that such a behavior leads to the presence of instabilities, which increase the complexity of the control of the overall packaging process.

Therefore, a need is felt in the sector to improve the packaging apparatuses. In particular, so as to overcome at least one of the above-mentioned disadvantages.

DISCLOSURE OF INVENTION

It is therefore an object of the present invention to provide in a straightforward and low-cost manner an improved packaging apparatus.

According to the present invention, there is provided a packaging apparatus as claimed in claim 1.

Further advantageous embodiments of the packaging apparatus according to the invention are specified in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a packaging apparatus according to the present invention, with parts removed for clarity;

FIG. 2 is a schematic view of details of the packaging apparatus of FIG. 1, with parts removed for clarity;

FIG. 3 is an enlarged partially sectionized view of a portion of the packaging apparatus of FIG. 1, with parts removed for clarity; and

FIG. 4 is a perspective view of a detail of the portion of FIG. 3, with parts removed for clarity; and

FIG. 5 is an enlarged sectionized view of the portion of FIG. 3, with parts removed for clarity.

BEST MODES FOR CARRYING OUT THE INVENTION

Number 1 indicates as a whole a packaging apparatus for producing sealed packages 2 of a pourable food product, in particular a sterilized and/or a sterile-processed pourable food product, such as pasteurized milk or fruit juice, from a tube 3 of a web 4 of packaging material. In particular, in use, tube 3 extends along a longitudinal axis L, in particular, axis L having a vertical orientation.

Web 4 of packaging material has a multilayer structure (not shown), and comprises at least one layer of fibrous material, such as e.g. a paper or cardboard layer, and at least two layers of heat-seal plastic material, e.g. polyethylene, interposing the layer of fibrous material in between one another. One of these two layers of heat-seal plastic material defining the inner face of package 2 eventually contacting the pourable product.

Preferably but not necessarily, web 4 also comprises a layer of gas- and light-barrier material, e.g. aluminum foil or ethylene vinyl alcohol (EVOH) film, in particular being arranged between one of the layers of the heat-seal plastic material and the layer of fibrous material. Preferentially but not necessarily, web 4 also comprises a further layer of heat-seal plastic material being interposed between the layer of gas- and light-barrier material and the layer of fibrous material.

A typical package 2 obtained by packaging apparatus 1 comprises a sealed longitudinal seam portion 5 and a pair of transversal seal portions 6, in particular a top transversal seal portion and a bottom transversal seal portion (i.e. one transversal seal portion 6 at an upper portion of package 2 and another transversal seal portion 6 at a lower portion of package 2).

With particular reference to FIGS. 1 and 2, packaging apparatus 1 comprises:

-   -   a conveying device 7 configured to advance web 4 (in a manner         known as such) along a web advancement path P from a delivery         station 8 to a tube forming station 9, at which, in use, web 4         is formed into tube 3;     -   an isolation chamber 10 having an inner environment 11, in         particular an inner sterile environment, containing (comprising)         a sterile gas, in particular sterile air, and being separated         from an outer environment 12;     -   a tube forming and sealing device 13 being at least partially         arranged within isolation chamber 10 and being adapted to form         and longitudinally seal tube 3, in particular at tube forming         station 9, within inner environment 11 and from the, in use,         advancing web 4;     -   a filling device 14 for filling tube 3 with the pourable         product; and     -   in particular, a package forming unit 15 adapted to form, to         transversally seal and, preferably but not necessarily to         transversally cut the, in use, advancing tube 3 for forming         packages 2.

Preferably but not necessarily, packaging apparatus 1 also comprises a sterilizing unit (not shown and known as such) adapted to sterilize, in particular by means of chemical and/or physical sterilization, the, in use, advancing web 4 at a sterilization station, in particular the sterilization station being arranged upstream of tube forming station 9 along web advancement path P.

Preferentially but not necessarily, conveying device 7 is configured to advance tube 3 and, in particular also any intermediate of tube 3, in a manner known as such along a tube advancement path Q, in particular from tube forming station 9 to and at least partially through package forming unit 15.

In particular, with the wording intermediates of tube 3 any configuration of web 4 is meant prior to obtaining the tube structure and after folding of web 4 by tube forming device 13 has started. In other words, the intermediates of tube 3 are a result of the gradual folding of web 4 so as to obtain tube 3, in particular by overlapping the lateral edges of web 4 with one another.

Preferentially but not necessarily, tube forming and sealing device 13 comprises a tube forming unit 22 at least partially, preferably fully, arranged within isolation chamber 10, in particular at tube forming station 9, and being adapted to (configured to) gradually fold the advancing web 4 into tube 3, in particular by overlapping the lateral edges with one another, for forming a longitudinal seam portion 23 of tube 3. In particular, tube forming unit 22 extends along a longitudinal axis M, in particular having a vertical orientation.

In particular, seam portion 23 extends from an initial level (not specifically shown) into a downward direction along tube advancement path Q. In other words, the initial level is at the position at which the lateral edges start to overlap one another for forming seam portion 23.

In particular, at least a portion of tube advancement path Q lies within isolation chamber 10 (in particular, within inner environment 11) and, even more particular another portion of tube advancement path Q lies within package forming unit 15.

In more detail, axis L and axis M are parallel to one another. In even more detail, tube forming unit 22 defines, in use, axis L of tube 3.

Preferentially but not necessarily, tube forming unit 22 comprises at least two forming ring assemblies 24 and 25, in particular arranged within isolation chamber 10 (in particular, within inner environment 11), being adapted to gradually fold in cooperation with one another web 4 into tube 3, in particular by overlapping the lateral edges of web 4 with one another.

Even more particular, forming ring assemblies 24 and 25 are spaced apparat from and parallel to one another.

Preferentially but not necessarily, tube forming and sealing device 13 also comprises a sealing unit adapted to (configured to) longitudinally seal tube 3 along seam portion 23. In other words, in use, seam portion 23 formed by tube forming unit 22 is sealed by activation of the sealing unit.

Preferentially but not necessarily, the sealing unit is at least partially positioned within isolation chamber 10.

It must be noted that the respective longitudinally sealed seam portion 5 of the single packages 2 result from cutting tube 3. In other words, the respective seam portions 5 of the single packages 2 are respective sections of seam portion 23 of tube 3.

Furthermore, the sealing unit comprises a sealing head 29 arranged within isolation chamber 10 and being adapted to (configured to) transfer thermal energy to tube 3, in particular to seam portion 23, for longitudinally sealing tube 3, in particular seam portion 23. Sealing head 29 can be of any type. In particular, sealing head 29 can be of the kind operating by means of induction heating and/or by a stream of a heated gas and/or by means of ultrasound and/or by laser heating and/or by any other means.

Preferentially but not necessarily, the sealing unit also comprises a pressing assembly (only partially shown) adapted to exert a mechanical force on tube 3, in particular onto seam portion 23, so as to ensure the longitudinal sealing of tube 3 along seam portion 23.

With particular reference to FIGS. 1 to 3 and 5, filling device 14 comprises a filling pipe 31 for directing the pourable product, in use, into tube 3. In particular, filling pipe 31 is in fluid connection or is controllable to be in fluid connection with a pourable product storage tank (not shown and known as such), which is adapted to store/provide for the pourable product, in particular the sterilized and/or sterile-processed pourable food product, to be packaged.

Preferentially but not necessarily, filling pipe 31 is, in use, at least partially placed within tube 3.

In particular, filling pipe 31 comprises a linear main pipe portion 32 extending within and parallel to tube 3, i.e. parallel to axis M and/or axis L.

Preferentially but not necessarily, main pipe portion comprises an upper section 33 and a lower section 34 removably coupled to one another. In further detail, lower section 34 comprises an outlet opening from which the pourable product is fed, in use, into tube 3.

According to the preferred non-limiting embodiment as shown in FIG. 2, package forming unit 15 comprises a plurality of pairs of at least one respective operative assembly 35 (only one shown) and at least one counter-operative assembly 36 (only one shown); and

-   -   in particular, a conveying device (not shown and known as such)         adapted to advance the respective operative assemblies 35 and         the respective counter-operative assemblies 36 of the pairs         along respective conveying paths.

In more detail, each operative assembly 35 is adapted to cooperate, in use, with the respective counter-operative assembly 36 of the respective pair for forming a respective package 2 from tube 3. In particular, each operative assembly and the respective counter-operative assembly 36 are configured to shape, to transversally seal and, preferably but not necessarily also to transversally cut, tube 3 for forming packages 2.

In further detail, each operative assembly 35 and the respective counter-operative assembly 36 are adapted to cooperate with one another for forming a respective package 2 from tube 3 when advancing along a respective operative portion of the respective conveying path. In particular, during advancement along the respective operative portion each operative assembly 35 and the respective counter-operative assembly 36 advance parallel to and in the same direction as tube 3.

In even more detail, each operative assembly 35 and the respective counter-operative assembly 36 are configured to contact tube 3 when advancing along the respective operative portion of the respective conveying path.

More specifically, each operative assembly 35 and counter-operative assembly 36 comprises:

-   -   a half-shell 37 adapted to contact tube 3 and to at least         partially define the shape of packages 2;     -   one of a sealing element 38 or a counter-sealing element 39,         adapted to transversally seal tube 3 in a known manner between         adjacent packages 2 for obtaining transversal seal portions 6;         and     -   preferably but not necessarily, one of a cutting element (not         shown and known as such) or a counter-cutting element (not shown         and known as such) for transversally cutting tube 3 between         adjacent packages 2, in particular between the respective         transversal seal portions 6, in a manner known as such.

In particular, each half-shell 37 is adapted to be controlled between a working position and a rest position by means of a driving assembly (not shown). In particular, each half-shell 37 is adapted to be controlled into the working position with the respective operative assembly 35 or the respective counter-operative assembly 36, in use, advancing along the respective operative portion.

With particular reference to FIGS. 1 and 2, isolation chamber 10 comprises an outlet-opening for allowing tube 3 to exit isolation chamber 10 during advancement along path Q. In particular, the outlet-opening is arranged downstream of tube forming station 9 along path Q.

Preferably but not necessarily, the outlet-opening is arranged in the area of a downstream (end) portion of isolation chamber 10.

Preferentially but not necessarily, isolation chamber 10 also comprises an inlet-opening, opposite to the outlet-opening, and configured to allow entrance of (sterile) web 4 into isolation chamber 10. In particular, the inlet-opening is positioned in an upstream portion of isolation chamber 10.

According to the preferred non-limiting embodiment disclosed, inner environment 11 comprises (i.e. contains) the sterile gas, in particular the sterile air, at a given pressure. Preferentially but not necessarily, the given pressure is (slightly) above ambient pressure for reducing the risk of any contaminants and/or contaminations entering inner environment 11. In particular, the given pressure is about 100 Pa to 500 Pa (0.001 bar to 0.005 bar) above ambient pressure.

According to the present invention and with particular reference to FIGS. 1 to 5, packaging apparatus 1 also comprises a delimiting element 45 moveably arranged, in use, within tube 3 and designed to divide tube 3, in use, into a first space 46 and a second space 47.

According to a preferred non-limiting embodiment, delimiting element 45 is arranged within isolation chamber 10, in particular upstream of the outlet-opening along tube advancement path Q.

In more detail, first space 46 is delimited by tube 3, in particular the walls of tube 3, and delimiting element 45. Furthermore, first space 46 opens up into inner environment 11. Even more particular, delimiting element 45 delimits first space 46 at a downstream portion (with respect to tube advancement path Q), in particular a bottom portion, of first space 46 itself.

In more detail, second space 47 is delimited, in use, by tube 3, in particular the walls of tube 3, delimiting element 45 and the transversal seal portion 6 of one respective package 2 (to be formed).

In other words, second space 47 extends in a direction parallel to tube advancement path Q (i.e. parallel to axis L) from delimiting element 45 to transversal seal portion 6.

In even other words, delimiting element 45 delimits second space 47 at an upstream portion (with respect to tube advancement path Q), in particular an upper portion, of second space 47 itself; and transversal seal portion 6 delimits second space 47 at a downstream portion (with respect to tube advancement path Q), in particular a bottom portion, of second space 47 itself.

In further detail, first space 46 is arranged upstream of second space 47 along tube advancement path Q. Even more particular, first space 46 is arranged upstream of delimiting element 45 along tube advancement path Q and second space 47 is arranged downstream of delimiting element 45 along tube advancement path Q. In the specific example shown, second space 47 is arranged below first space 46.

Advantageously and with particular reference to FIGS. 1 and 2, packaging apparatus 1 comprises a sterile gas supply device 48 (only partially shown to the extent necessary for the comprehension of the invention disclosed) configured to at least direct a main flow of sterile gas into second space 47 in such a manner that the gas pressure of the sterile gas within second space 47 is higher than the gas pressure of the sterile gas present within isolation chamber 10 and/or inner environment 11 and/or first space 46.

Preferentially but not necessarily, sterile gas supply device 48 is also adapted to (configured to) direct, in use, a further flow of sterile gas (not specifically shown) into isolation chamber 10 and/or inner environment 11.

In particular, second space 47 defines a high-pressure zone within tube 3 and first space 46 defines a low-pressure zone within tube 3. In the context of the present application, high-pressure zone is to be understood such that the internal pressure lies in a range of about 5 kPa to 40 kPa (0.05 bar to 0.40 bar), in particular of about 10 kPa to 30 kPa (0.10 bar to 0.30 bar) above ambient pressure (i.e. the pressure within second space 47 lies in a range of about 5 kPa to 40 kPa (0.05 bar to 0.40 bar), in particular of about 10 kPa to 30 kPa (0.10 bar to 0.30 bar) above ambient pressure). In other words, second space 47 is overpressurized with respect to first space 46.

Low-pressure zone is to be understood such that the pressure is slightly higher than the ambient pressure. In particular, only slightly higher than the ambient pressure means that the pressure lies preferably in a range between 100 Pa to 500 Pa (0.001 bar to 0.005 bar) above ambient pressure.

Preferably but not necessarily, first space 46 is in (direct) fluidic connection with inner environment 11. Thus, sterile gas present in the first space 46 can flow to inner environment 11.

In particular, tube 3 (and its intermediates) lie(s) at least partially within isolation chamber 10 (in particular, within inner environment 11).

Preferentially, the pressure inside first space 46 (substantially) equals the given pressure present in isolation chamber 10, in particular in inner environment 11.

According to a preferred non-limiting embodiment, delimiting element 45 is arranged, in use, downstream of the above-mentioned initial level along tube advancement path Q. In other words, delimiting element 45 is positioned below the point from which seam portion 23 extends along a downstream direction (with respect to tube advancement path Q). In even other words, delimiting element 45 is arranged below the position from which the lateral edges of web 4 are superimposed for forming seam portion 23.

Furthermore, in use, filling device 14, in particular filling pipe 31, is adapted to (configured to) direct the pourable product into second space 47. Thus, in use, second space 47 contains the pourable product and the pressurized sterile gas directed into the second space 47. The pressurized sterile gas provides for the required hydrostatic force needed for a correct forming of packages 2.

Advantageously but not necessarily and with particular reference to FIGS. 1 to 5, sterile gas supply device 48 comprises a gas supply pipe 49 configured to direct the main flow of sterile gas into second space 47; in other words, in use, the main flow of sterile gas enters into second space 47 through gas supply pipe 49.

In particular, gas supply pipe 49 comprises an outlet mouth 50 configured to allow for the main flow of sterile gas exiting gas supply pipe 49, and in particular entering into second space 47.

Preferentially but not necessarily, gas supply pipe 49 also comprises a collar portion 51 surrounding and/or delimiting outlet mouth 50.

In particular, gas supply pipe 49, in particular outlet mouth 50 and/or collar portion 51, is arranged upstream of delimiting element 45 along tube advancement path Q.

Preferentially but not necessarily, gas supply pipe 49 within tube 3. In particular, main portion 52 extends parallel, preferentially but not necessarily coaxial, to main pipe portion 32.

According to a preferred non-limiting embodiment, main portion 52 carries and/or comprises outlet mouth 50 and/or collar portion 51.

In the specific example shown, filling pipe 31 extends at least partially within gas supply pipe 49. Alternatively, gas supply pipe 49 could at least partially extend within filling pipe 31.

In more detail, at least main pipe portion 32 extends at least partially within main portion 52.

In particular, the cross-sectional diameter of main pipe portion 32 is smaller than the cross-sectional diameter of main portion 52.

Preferentially but not necessarily, gas supply pipe 49 and filling pipe 31 define/delimit an annular conduit 53 for the main flow of sterile gas to be fed into second space 47. In particular, annular conduit 53 is delimited by the inner surface of gas supply pipe 49 and the outer surface of filling pipe 31.

According to a preferred non-limiting embodiment, delimiting element 45 comprises a passage 57, in particular having a circular cross-sectional profile, configured to allow the main flow to enter into second space 47 through passage 57. In particular, passage 57 is, in use, arranged substantially coaxial to filling pipe 31 and/or gas supply pipe 49, in particular outlet mouth 50, and/or longitudinal axis M and/or longitudinal axis L.

Preferentially but not necessarily, filling pipe 31, in particular main pipe portion 32, extends through passage 57 into second space 47.

Preferentially but not necessarily, a central rim portion 58 of delimiting element 45 delimits passage 57 and central rim portion 58 defines and/or delimits together with filling pipe 31, in particular main pipe portion 32, a ring-shaped channel 59 through which, in use, the main flow of sterile gas enters into second space 47.

In particular, in use, the main flow of gas exits from gas supply pipe 49 through outlet mouth 50 and enters into second space 47 through ring-shaped channel 59.

Advantageously, delimiting element 45 is arranged such that delimiting element 45 is adapted to move along a first direction D1 and a second direction D2 being opposite to first direction D1. First direction D1 and second direction D2 being (substantially) parallel to longitudinal axis L and/or tube 3 and/or longitudinal axis M. Furthermore, delimiting element 45 is adapted to (configured to) move between at least a first position and a second position, in particular a first end position and a second end position. In particular, in use, when moving along first direction D1 and along second direction D2 delimiting element 45 moves respectively towards and away from gas supply pipe 49.

According to a preferred non-limiting embodiment, the first position is upstream of the second position along tube advancement path Q. In the particular non-limiting embodiment shown, delimiting element 45 is configured to move downwards from the first position to the second position and upwards from the second position to the first position.

In particular as will be disclosed in the following, the first position and the second position of delimiting element 45 are delimited and/or defined by respective parts of packaging apparatus 1.

According to a preferred non-limiting embodiment, delimiting element 45 is also adapted to move along a third direction D3 and a fourth direction D4 being opposite to third direction D3. Third direction D3 and fourth direction D4 are transversal, in particular perpendicular, to longitudinal axis L and/or longitudinal axis M and/or first direction D1 and/or second direction D2.

Advantageously, delimiting element 45 comprises a main engagement portion 60 configured to abut against a main abutment portion 61 of gas supply pipe 49 or of filling pipe 31, in the specific case shown in FIGS. 1 to 5 of gas supply pipe 49, with delimiting element 45 being in the first position.

Preferentially but not necessarily, main abutment portion 61 and/or main engagement portion 60 have an annular shape.

Advantageously, main abutment portion 61 and/or main engagement portion 60 are designed such that one or more openings 62 and/or one or more channels are present between main abutment portion 61 and main engagement portion 60 with delimiting element 45 being in the first position.

Advantageously, openings 62 and/or the channels are configured such to establish a fluid connection between inner environment 11 and gas supply pipe 49 and/or second space 47 through the channels and/or openings 62, in particular so as to allow, in use, for the occurrence of an auxiliary flow of gas between main abutment portion 61 and main engagement portion 60 also with delimiting element 45 being in the first position. In this way, it is guaranteed independently of the position of the delimiting element 45 that there is the presence of the auxiliary flow. Furthermore, this means that no changes between the presence of the auxiliary flow and the complete interruption occurs as it is the case with respect to the state-of-the-art package apparatus as described in the introductive part. It should be noted that the effective auxiliary flow is dependent on the distance of delimiting element 45 from main abutment portion 61, however, these variations introduce significantly less instability than the case in which sometimes there is an auxiliary flow and other times there is not.

Preferentially but not necessarily, collar portion 51 comprises main abutment portion 61 with main abutment portion facing delimiting element 45, in particular main engagement portion 60.

According to a preferred non-limiting embodiment, delimiting element 45 comprises a main portion 63 facing gas supply pipe 49, in particular outlet mouth 50 and/or collar portion 51. In particular, main portion 63 carries and/or comprises and/or supports main engagement portion 60.

Preferentially but not necessarily, main portion 63 comprises and/or is provided with passage 57.

According to a preferred non-limiting embodiment and with particular reference to FIG. 4, delimiting element 45 comprises one or more spacer elements 64 facing and protruding towards main abutment portion 61 and/or gas supply pipe 49. In particular, spacer elements 64 carry and/or comprise and/or define, in particular in cooperation, main engagement portion 60.

In particular, spacer elements 64 protrude from main portion 62.

Preferentially but not necessarily, each spacer element 64 has an arc-shaped profile.

Preferentially but not necessarily, spacer elements 64 surround passage 58 and are spaced apart from one another around passage 58 so as to form openings 62. In particular, neighboring spacer elements 64 do not contact one another in order to form openings 62.

According to an alternative embodiment not shown, neighboring elements 64 could be connected with one another by means of a bridge portion also partially delimiting the respective opening 62.

In use, with delimiting element 45 being in the first position spacer elements 64 guarantee that there is a space between main portion 63 and collar portion 51 and openings 62 guarantee that the auxiliary flow of sterile gas flows also with delimiting element 45 being in the first position.

Alternatively or in addition, main engagement portion 60 and/or main abutment portion 61 comprises one or more grooves defining the one or more channels.

According to a preferred non-limiting embodiment and with particular reference to FIGS. 3 and 5, packaging apparatus 1 further comprises a support element 65 having an auxiliary abutment portion 66 and delimiting element 45 comprises an auxiliary engagement portion 67, in particular opposite to main engagement portion 60, configured to abut against auxiliary abutment portion 66 with delimiting element 45 being in the second position.

In particular, delimiting element 45 is interposed between main abutment portion 61 and auxiliary abutment portion 66. Even more particular, in use, when delimiting element 45 moves along first direction D1 and second direction D2, delimiting element 45 moves towards respectively main abutment portion 61 and auxiliary abutment portion 66.

According to the non-limiting embodiment shown, delimiting element 45 is interposed between gas supply pipe and support element 65. Thus, movement of delimiting element 45 along first direction D1 and second direction D2 is delimited by respectively and between gas supply pipe 49 and support element 65.

Preferentially but not necessarily, support element 65 is connected to filling pipe 31 and/or gas supply pipe 49. In the non-limiting embodiment shown, filling pipe 31 is connected to filling pipe 31, in particular main pipe portion 32, and protrudes towards gas supply pipe 49.

According to a preferred non-limiting embodiment, a first end portion 68 of support element 65 is connected to filling pipe 31 and a second end portion 69 of support element 65 opposite to first end portion 68 comprises auxiliary abutment portion 66.

In particular, when sterile gas supply device 48 is deactivated second space 47 does not contain the pressurized sterile gas, delimiting element 45 is supported by and/or “sits” on support element 65.

According to a preferred non-limiting embodiment, support element 65 has a truncated cone shape and is hollow. In particular, support element 65 also comprises a plurality of apertures 70 for the main flow of the sterilized gas.

According to a preferred non-limiting embodiment and with particular reference to FIGS. 2 and 5, delimiting element 45 is designed to provide, in use, and in collaboration with tube 3 for at least one fluidic channel 71, in particular having an annular shape, for fluidically connecting second space 47 with first space 46 allowing for, in use, a direct leakage flow of sterile gas from second space 47 into first space 46. In particular, in use, the sterile gas leaks from second space 47 (the high-pressure zone) to first space 46 (the low-pressure zone) through fluidic channel 71. By providing for fluidic channel 71 it is possible to control the gas pressure within second space 47 with an increased accuracy.

Preferentially but not necessarily, in use, delimiting element 45 is designed such that, in use, fluidic channel 71 is provided by a gap between the inner surface of tube 3 and delimiting element 45, in particular a peripheral portion of delimiting element 45.

According to a preferred non-limiting embodiment, delimiting element 45 has a radial extension being smaller than the inner diameter of tube 3.

Preferentially but not necessarily, sterile gas supply device 48 is configured to allow for a variable main flow of sterile gas (i.e. adapted to control varying flow rates) by maintaining a substantially constant gas pressure within second space 47 at various flow rates.

Preferentially but not necessarily, sterile gas supply device 48 is adapted to vary the main flow of sterile gas in dependence of the volume of the sterile gas flowing from second space 47 to first space 46, in particular through at least fluidic channel 71.

Preferentially but not necessarily, sterile gas supply device 48 is adapted to (configured to) control the gas pressure within second space 47 to range between 5 kPa to 40 kPa (0.05 bar to 0.40 bar), in particular between 10 kPa to 30 kPa (0.10 bar to 0.30 bar), above ambient pressure.

Advantageously but not necessarily and with particular reference to FIGS. 1 and 2, sterile gas supply device 48 comprises a closed sterile gas circuit from inner environment 11 into second space 47 and back into inner environment 11. This allows a simplified overall construction of packaging apparatus 1, in particular related to the control and the supply of the sterile gas.

According to the preferred non-limiting embodiment disclosed, sterile gas supply device 48 is adapted to withdraw sterile gas from inner environment 11, to pressurize (to compress) the sterile gas and to direct the pressurized (compressed) sterile gas into second space 47.

Preferentially but not necessarily, sterile gas supply device 48 comprises at least one pumping device 74 configured to withdraw sterile gas from inner environment 11, to pressurize (to compress) the sterile gas and to direct the pressurized sterile gas into second space 47.

Preferentially but not necessarily, pumping device 74 is a rotary machine, even more particular a compressor.

Preferentially but not necessarily, sterile gas supply device 48 also comprise:

-   -   a gas conduit 75 being in direct fluidic connection with pumping         device 74 and gas supply pipe 49; and     -   a gas conduit 76 being in direct fluidic connection with inner         environment 11 and pumping device 74.

Thus, in use, sterile gas is withdrawn from inner environment 11 through gas conduit 76, is pressurized (compressed) by pumping device 74 and is then directed into second space 47 through gas conduit 75 and gas supply pipe 49.

In use, packaging apparatus 1 forms packages 2 filled with a pourable product. In particular, packaging apparatus 1 forms packages 2 from tube 3 formed from web 4, tube 3 being continuously filled with the pourable product.

In more detail, operation of packaging apparatus 1 comprises:

-   -   a first advancement step for advancing web 4 along path P;     -   a tube forming and sealing step during which web 4 is formed         into tube 3 and tube 3 is longitudinally sealed, in particular         along seam portion 23;     -   a second advancement step during which tube 3 is advanced along         path Q;     -   a filling step during which the pourable product is filled into         tube 3; and     -   a package forming step during which packages 2 are formed from         tube 3, in particular by shaping (respective (lower) portions)         of tube 3 and transversally sealing and cutting tube 3.

In further detail, the tube forming and sealing step comprises the sub-step of gradually overlapping the lateral edges of tube 3 with one another for forming seam portion 23 and the sub-step of longitudinally sealing tube 3.

The filling step comprises the sub-step of directing the pourable product through filling pipe 31 into second space 47.

During the package forming step, packages 2 are formed by operation of package forming unit 15, which receives tube 3 after the tube forming and sealing step. In particular, during the package forming step operative assemblies 35 and counter-operative assemblies 36 advance along their respective conveying paths. When operative assemblies 35 and their respective counter-operative assemblies 36 advance along their respective operative portions, operative assemblies 35 and the respective counter-operative assemblies 36 cooperate with one another for shaping, transversally sealing and, preferably but not necessarily, transversally cutting advancing tube 3 so as to form packages 2. During the package forming step, the pourable product is directed into second space 47 so as to obtain filled packages 2.

Operation of packaging apparatus 1 also comprises a pressurizing step during which sterile gas, in particular the pressurized (compressed) sterile gas is directed into second space 47.

In more detail, during the pressurizing step, sterile gas is directed, in particular continuously directed, into second space 47 for obtaining a gas pressure within second space 47 which ranges between 5 kPa to 40 kPa (0.05 bar to 0.40 bar), in particular between 10 kPa to 30 kPa (0.10 bar to 0.30 bar), above ambient pressure.

In particular, second space 47 contains the pourable product and the pressurized sterile gas.

Preferentially but not necessarily, during the pressurizing step the auxiliary flow of sterile gas flows between main abutment portion 61 and main engagement portion 60 independently of the position of delimiting element 45 between the first portion and the second position.

Preferentially but not necessarily, the leakage flow of sterile gas is established from second space 47 to first space 46 through fluidic channel 71.

According to a preferred non-limiting embodiment, during the pressurizing step, the sterile gas is withdrawn from isolation chamber 10, in particular from inner environment 11, is pressurized (compressed) and then directed, in particular continuously directed, into second space 47.

In even further detail, during the pressurizing step, pumping device 74 withdraws the sterile gas from isolation chamber 10, in particular from inner environment 11, pressurizes (compresses) the sterile gas and directs the pressurized (compressed) gas through gas supply pipe 49 into second space 47.

The advantages of packaging apparatus 1 according to the present invention will be clear from the foregoing description.

In particular, by providing for openings 62 and/or the channels it is guaranteed that there is always an auxiliary gas flow between main abutment portion 61 and main engagement portion 60 even when delimiting element 45 is in the first position. This increases the stability of the whole system as the complete shut-off of the auxiliary flow (as in the state-of-art packaging apparatuses) decreases the stability. Accordingly, the control of packaging apparatus 1 is facilitated with respect to the state-of-the-art packaging apparatuses.

Clearly, changes may be made to packaging apparatus 1 as described herein without, however, departing from the scope of protection as defined in the accompanying claims.

According to an alternative embodiment not shown, gas supply pipe 49 could take the place of filling pipe 31 and filling pipe 31 could take the place of gas supply pipe 49. 

1. A packaging apparatus for forming a plurality of sealed packages filled with a pourable product comprising: a conveying device adapted to advance a web of packaging material along an advancement path; an isolation chamber separating an inner environment containing a sterile gas from an outer environment; a tube forming and sealing device being at least partially arranged within the isolation chamber and being adapted to form and longitudinally seal a tube extending along a longitudinal axis from the, in use, advancing web of packaging material; wherein the conveying device is also adapted to advance the tube along a tube advancement path; a delimiting element moveably arranged, in use, within the tube and designed to divide the tube in a first space being in fluidic connection with the inner environment and a second space being arranged downstream of the first space along the tube advancement path; a filling device having a filling pipe arranged, in use, within the tube and being adapted to direct, in use, a pourable product through the filling pipe into the second space; a sterile gas supply device having a gas supply pipe being arranged, in use, within the tube and being configured to direct through the gas supply pipe a main flow of sterile gas into the second space in such a manner that the gas pressure within the second space is higher than the gas pressure within the isolation chamber; wherein the delimiting element is arranged such that the delimiting element is adapted to move into a first direction and a second direction being opposite to the first direction and the first direction and the second direction being substantially parallel to the longitudinal axis of the tube and between at least a first position and a second position; wherein the gas supply pipe or the filling pipe comprises a main abutment portion; wherein the delimiting element comprises a main engagement portion configured to abut against the main abutment portion with the delimiting element being in the first position; wherein the main abutment portion and/or the main engagement portion are designed such that at least one opening and/or at least one channel is present between the main abutment portion and the main engagement portion with the delimiting element being in the first position; wherein the at least one opening and/or the at least one channel are configured such to establish a fluid connection between the inner environment and the gas supply pipe and/or the second space through at least one opening and/or the at least one channel.
 2. Packaging apparatus according to claim 1, wherein the delimiting element comprises at least one spacer element facing and protruding towards the main abutment portion; wherein the spacer element defines and/or comprises and/or carries the main engagement portion.
 3. Packaging apparatus according to claim 2, wherein the spacer element has an arc-shaped profile.
 4. Packaging apparatus according to claim 2, wherein the delimiting element comprises a plurality of spacer elements surrounding a passage and being arranged such to form at least one opening.
 5. Packaging apparatus according to claim 2, wherein the passage is coaxial to the gas supply pipe and/or the filling pipe.
 6. Packaging apparatus according to claim 1, wherein the main engagement portion and/or the main abutment portion comprises one or more grooves defining one or more channels.
 7. Packaging apparatus according to claim 1, wherein the main abutment portion and/or the main engagement portion have an annular shape.
 8. Packaging apparatus according to claim 1, and further comprising a support element having an auxiliary abutment portion; wherein the delimiting element comprises an auxiliary engagement portion configured to abut against the auxiliary abutment portion with the delimiting element being in the second position.
 9. Packaging apparatus according to claim 8, wherein the support element is connected to the filling pipe and/or the gas supply pipe.
 10. Packaging apparatus according to claim 1, wherein the delimiting element is arranged within the isolation chamber.
 11. Packaging apparatus according to claim 1, wherein the tube forming and sealing device comprises a tube forming unit configured to gradually fold the web of packaging material into the tube by overlapping the lateral edge of the web of packaging material with one another for forming a longitudinal seam portion; wherein the seam portion extends from an initial level along a downstream direction along the tube advancement path; wherein the delimiting element is arranged in the area of the initial level and/or downstream of the initial level along the tube advancement path.
 12. Packaging apparatus according to claim 1, wherein the delimiting element is designed such to provide, in use, at least one fluidic channel delimited by a peripheral portion of the delimiting element and the inner surface of the, in use, advancing tube for fluidically connecting the second space with the first space and for allowing, in use, a leakage flow of sterile gas from the second space into the first space.
 13. Packaging apparatus according to claim 1, wherein the delimiting element is adapted to move along a direction perpendicular to the, in use, advancing tube.
 14. Packaging apparatus according to claim 1, wherein at least a portion of the gas feeding pipe and at least a portion of the filling pipe are parallel to one another. 